KR20220147092A - Polyimide resins, polyimide varnishes and polyimide films - Google Patents

Abstract

A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, wherein the structural unit A is a structural unit derived from a compound represented by the following formula (a1): It contains a structural unit (A2) derived from the compound represented by formula (a2), wherein the structural unit B is represented by a structural unit (B1) derived from a compound represented by the following formula (b1), and the following formula (b21) A polyimide resin comprising at least one structural unit (B2) selected from the group consisting of a structural unit (B21) derived from a compound to be used and a structural unit (B22) derived from a compound represented by the following formula (b22).

Description

Polyimide resins, polyimide varnishes and polyimide films

The present invention relates to polyimide resins, polyimide varnishes and polyimide films.

Various uses of polyimide resin are considered in the field|area, such as an electric and electronic component. For example, it is desired to replace a glass substrate used in an image display apparatus such as a liquid crystal display or an OLED display with a plastic substrate for the purpose of weight reduction and flexibility of the device, and a polyimide film suitable as the plastic substrate research is in progress.

Films used for image display applications are required to have various optical properties. For example, when light emitted from a display device is emitted through a plastic substrate, colorless and transparent properties are required for the plastic substrate.

In order to satisfy the above performance, the development of polyimide resins of various compositions is being carried out. For example, Patent Document 1 contains polyamide having good solubility in a solvent and excellent workability, is colorless and transparent, and for the purpose of obtaining a polyimide film excellent in toughness, as a diamine component, 3,3 A polyimide film comprising a structure composed of a combination of '-diaminodiphenylsulfone and other specific diamines is disclosed.

International Publication No. 2016/158825

In addition to colorless transparency, when light passes through a retardation film or a polarizing plate, for example, when used in a liquid crystal display, a touch panel, etc., particularly high optical isotropy (ie, low Rth) is required.

Furthermore, a polyimide film with high chemical-resistance is also calculated|required. For example, when a varnish for forming the resin layer is applied to the polyimide film to form another resin layer (eg, color filter, resist) on top of the polyimide film, the polyimide film is included in the varnish. Resistance to solvents and the like is required. When the solvent resistance of a polyimide film is inadequate, there exists a possibility that it may become meaningless as a board|substrate by melt|dissolution and swelling of a film. However, in order to secure the optical properties as described above, it is necessary to use a solution when preparing the polyimide film, and it is difficult to achieve both properties.

Moreover, when using a polyimide film as a board|substrate, there exists a process of peeling a polyimide film from a support body after circuit creation. In that case, a polyimide film is calculated|required to have fixed toughness, ie, favorable elongation, in the meaning of facilitating a process and preventing the fracture|rupture during peeling.

As described above, there has been a demand for a polyimide resin capable of obtaining a polyimide film excellent in stretching and chemical resistance while maintaining the optical properties, particularly optical isotropy, of the obtained polyimide film.

The present inventors discovered that the said subject can be solved by the polyimide resin containing the combination of the structural unit derived from 2 specific types of tetracarboxylic dianhydride, and the structural unit derived from 2 specific types of diamine, came to the conclusion of the invention.

That is, the present invention relates to the following <1> to <5>.

<1> A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, wherein the structural unit A is a structural unit derived from a compound represented by the following formula (a1) (A1) and a structural unit (A2) derived from a compound represented by the following formula (a2), wherein the structural unit B is a structural unit derived from a compound represented by the following formula (b1) (B1), and the following formula (b21) A polyimide containing at least one structural unit (B2) selected from the group consisting of a structural unit (B21) derived from a compound represented by ) and a structural unit (B22) derived from a compound represented by the following formula (b22) Suzy.

[Formula 1]

<2> In the above <1>, the proportion of the structural unit (A1) in the structural unit A is 30 to 90 mol%, and the proportion of the structural unit (A2) in the structural unit B is 10 to 70 mol% described polyimide resin.

<3> above <1>, wherein the ratio of the structural unit (B1) in the structural unit B is 5-80 mol%, and the ratio of the structural unit (B2) in the structural unit B is 20-95 mol%; or The polyimide resin according to <2>.

<4> A polyimide varnish in which the polyimide resin according to any one of <1> to <3> is dissolved in an organic solvent.

<5> The polyimide film containing the polyimide resin in any one of said <1>-<3>.

According to the present invention, a polyimide resin, a polyimide varnish capable of forming a film having excellent optical isotropy and excellent stretching and chemical resistance, and a polyimide film excellent in optical isotropy and also excellent in stretching and chemical resistance. can provide

[Polyimide resin]

The polyimide resin of the present invention is a polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, wherein the structural unit A is derived from a compound represented by the following formula (a1) It contains a structural unit (A1) and a structural unit (A2) derived from a compound represented by the following formula (a2), wherein the structural unit B is a structural unit derived from a compound represented by the following formula (b1) (B1) and , at least one structural unit (B2) selected from the group consisting of a structural unit (B21) derived from a compound represented by the following formula (b21) and a structural unit (B22) derived from a compound represented by the following formula (b22) (B2) includes

[Formula 2]

Although it is not clear why the polyimide resin of the present invention has excellent stretching and chemical resistance while maintaining optical isotropy, optical isotropy is excellent because it has an alicyclic structure, an aromatic structure, and an ether structure and a sulfonyl structure in an appropriate ratio. Furthermore, it is thought that it is excellent also in extending|stretching and chemical-resistance.

<composition unit A>

The structural unit A is a structural unit derived from the tetracarboxylic dianhydride occupied in the polyimide resin.

The structural unit A includes a structural unit (A1) derived from a compound represented by the following formula (a1) and a structural unit (A2) derived from a compound represented by the following formula (a2).

[Formula 3]

The compound represented by formula (a1) is 4,4'-oxydiphthalic anhydride.

When the structural unit A contains the structural unit (A1), chemical resistance and elongation can be improved.

The compound represented by formula (a2) is 1,2,4,5-cyclohexanetetracarboxylic dianhydride.

When the structural unit A contains a structural unit (A2), transparency and optical isotropy can be improved, improving the solubility to the varnish of the polyimide resin obtained.

The proportion of the structural unit (A1) in the structural unit A is preferably 30 to 90 mol%, more preferably 35 to 70 mol%, and still more preferably 40 to 60 mol%.

The proportion of the structural unit (A2) in the structural unit A is preferably 10 to 70 mol%, more preferably 30 to 65 mol%, and still more preferably 40 to 60 mol%.

The ratio of the total of the structural units (A1) and (A2) in the structural unit A is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more. The upper limit is not particularly limited, and the proportion of the total of the structural units (A1) and (A2) in the structural unit A is 100 mol% or less. The constituent unit A may consist of only the constituent unit (A1) and the constituent unit (A2).

The molar ratio [(A1)/(A2)] of the structural unit (A1) to the structural unit (A2) in the structural unit A is preferably 30/70 to 90/ from the viewpoint of improving optical isotropy and chemical resistance. 10, more preferably 35/65 to 70/30, still more preferably 40/60 to 60/40.

The structural unit A may include structural units other than the structural unit (A1) and the structural unit (A2). The tetracarboxylic dianhydride giving such a structural unit is not particularly limited, but pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9,9'-bis( 3,4-dicarboxyphenyl) fluorene dianhydride and aromatic tetracarboxylic dianhydride such as 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (provided that the compound represented by the formula (a1) excluded); 1,2,3,4-Cyclobutanetetracarboxylic dianhydride, norbornane-2-spiro-α-cyclopentanone-α′-spiro-2′′-novonane-5,5′′,6,6 Alicyclics such as ''-tetracarboxylic acid dianhydride and 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6'-dianhydride Formula tetracarboxylic dianhydride (however, the compound represented by Formula (a2) is excluded); and aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride.

On the other hand, in the present specification, aromatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing one or more aromatic rings, and alicyclic tetracarboxylic dianhydride includes one or more alicyclic rings, and also aromatic rings It means tetracarboxylic dianhydride not containing, and aliphatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing neither aromatic rings nor alicyclics.

The structural unit arbitrarily included in the structural unit A may be one type or two or more types may be sufficient as it.

<Constituent Unit B>

The structural unit B is a structural unit derived from the diamine occupied in the polyimide resin.

The structural unit B is a structural unit (B1) derived from a compound represented by the following formula (b1), a structural unit (B21) derived from a compound represented by the following formula (b21), and a structural unit represented by the following formula (b22) At least one structural unit (B2) selected from the group consisting of a structural unit (B22) derived from a compound is included.

[Formula 4]

The compound represented by the formula (b1) is bis[(aminophenoxy)phenyl]sulfone, and specific examples thereof include bis[4-(4-aminophenoxy)phenyl]sulfone represented by the following formula (b1a); It is bis[4-(3-aminophenoxy)phenyl]sulfone represented by following formula (b1b). When the structural unit B contains the structural unit (B1), the stretching and chemical resistance of the film can be improved, and further, the heat resistance and optical isotropy can be improved.

[Formula 5]

The compound represented by the formula (b21) is bis(aminomethyl)cyclohexane, and specific examples thereof include 1,3-bis(aminomethyl)cyclohexane represented by the following formula (b21a) and the following formula (b21b) 1,4-bis(aminomethyl)cyclohexane represented by

[Formula 6]

From the viewpoint of organic solvent resistance and heat resistance, the cis:trans ratio of the compound represented by the formula (b21) is preferably 0:100 to 80:20, more preferably 0.1:99.9 to 70:30, and 0.5:99.5 ~60:40 is more preferable, and 1:99-20:80 is still more preferable.

The compound represented by formula (b22) is bis(aminomethyl) norbornane. Formula (b22) represents an isomer mixture, and the compound represented by Formula (b22) can be obtained as an isomer mixture.

When the structural unit B includes the structural unit (B2), transparency and optical isotropy of the film can be improved.

The proportion of the structural unit (B1) in the structural unit B is preferably 5-80 mol%, more preferably 10-70 mol%, and still more preferably 30-60 mol%.

The proportion of the structural unit (B2) in the structural unit B is preferably 20 to 95 mol%, more preferably 30 to 90 mol%, and still more preferably 40 to 70 mol%.

The ratio of the total of the structural units (B1) and (B2) in the structural unit B is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more. The upper limit is not particularly limited, and the proportion of the total of the structural units (B1) and (B2) in the structural unit B is 100 mol% or less. The constituent unit B may consist of only the constituent unit (B1) and the constituent unit (B2).

The molar ratio [(B1)/(B2)] of the structural unit (B1) to the structural unit (B2) in the structural unit B is preferably 5/95 to 80/ from the viewpoint of improving optical isotropy and chemical resistance. 20, more preferably 10/90 to 70/30, still more preferably 30/70 to 60/40. Moreover, from a viewpoint of heat resistance and extending|stretching, Preferably it is 25/75-80/20, More preferably, it is 35/65-65/35, More preferably, it is 35/65-55/45, More preferably is 35/65 to 45/55.

The structural unit B may include structural units other than the structural unit (B1) and the structural unit (B2). Although it does not specifically limit as a diamine giving such a structural unit, 1, 4- phenylenediamine, p-xylylene diamine, 1, 5- diamino naphthalene, 2,2'- dimethylbiphenyl-4,4' -Diamine, 4,4'-diaminodiphenyl ether, 4,4'-diamino-2,2'-bistrifluoromethyldiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2 -Bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminobenzanilide, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H- Inden-5-amine, α,α′-bis(4-aminophenyl)-1,4-diisopropylbenzene, N,N′-bis(4-aminophenyl)terephthalamide, 4,4′-bis( 4-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane; and aromatic diamines such as 9,9-bis(4-aminophenyl)fluorene (however, the compound represented by the formula (b1) is excluded); alicyclic diamines (however, the compound represented by the formula (b21) and the compound represented by the formula (b22) are excluded); and aliphatic diamines such as ethylenediamine and hexamethylenediamine.

On the other hand, in the present specification, the aromatic diamine means a diamine containing one or more aromatic rings, the alicyclic diamine means a diamine containing one or more alicyclic rings and does not contain an aromatic ring, and the aliphatic diamine is It means diamine which contains neither an aromatic ring nor an alicyclic ring.

The structural unit arbitrarily included in the structural unit B may be one type or two or more types may be sufficient as it.

<Characteristics of polyimide resin>

The weight average molecular weight of polyimide resin becomes like this from a viewpoint of the mechanical strength of the polyimide film obtained, Preferably it is 5,000-300,000. In addition, the weight average molecular weight of polyimide resin can be calculated|required from the standard polymethylmethacrylate (PMMA) conversion value by gel filtration chromatography measurement, for example.

The polyimide resin may contain structures other than the polyimide chain (the structure in which the structural unit A and the structural unit B are imide-bonded). As structures other than the polyimide chain which can be contained in polyimide resin, the structure etc. containing an amide bond are mentioned, for example.

The polyimide resin preferably contains, as a main structure, a polyimide chain (a structure in which the structural unit A and the structural unit B are imide bonds). Therefore, the proportion of the polyimide chain in the polyimide resin is preferably 50 mass % or more, more preferably 70 mass % or more, still more preferably 90 mass % or more, particularly preferably 99 mass % or more. or more, and is 100 mol% or less. The polyimide resin may consist only of a polyimide chain.

The polyimide resin composition of the present invention including the polyimide resin can form a film excellent in optical isotropy, stretching and chemical resistance, and suitable physical properties of the film are as follows.

When a total light transmittance is set as the film of 10 micrometers in thickness, Preferably it is 88 % or more, More preferably, it is 88.5 % or more, More preferably, it is 89 % or more.

The yellow index (YI) is preferably 5.0 or less, more preferably 3.0 or less, still more preferably 2.5 or less, still more preferably 2.0 or less when a film having a thickness of 10 µm is obtained.

The absolute value of the thickness retardation (Rth) is preferably 70 nm or less, more preferably 50 nm or less, even more preferably 35 nm or less, even more preferably 30 nm or less, when a film having a thickness of 10 µm is used. Preferably it is 20 nm or less.

In addition, the film that can be formed using the polyimide resin has good mechanical properties and heat resistance, and has the following suitable physical properties.

The tensile strength is preferably 70 MPa or more, more preferably 90 MPa or more, and still more preferably 100 MPa or more.

The tensile modulus of elasticity is preferably 1.5 GPa or more, more preferably 2.0 GPa or more, still more preferably 2.5 GPa or more, still more preferably 2.7 GPa or more.

The tensile elongation at break is preferably 8% or more, more preferably 10% or more, still more preferably 15% or more, still more preferably 20% or more.

The glass transition temperature (Tg) is preferably 200°C or higher, more preferably 230°C or higher, and still more preferably 250°C or higher.

In addition, the above-mentioned physical property value in this invention can be specifically measured by the method as described in an Example.

<Method for producing polyimide resin>

The polyimide resin of this invention contains the tetracarboxylic-acid component containing the compound which provides the compound which provides the above-mentioned structural unit (A1), and the compound which provides the above-mentioned structural unit (A2), and the above-mentioned structural unit (B1) It can manufacture by making the diamine component containing the compound which provides and the compound which provides the structural unit (B2) mentioned above react.

Although the compound represented by Formula (a1) is mentioned as a compound which provides a structural unit (A1), It is not limited to it, It may be a derivative|guide_body in the range which gives the same structural unit. Examples of the derivative include tetracarboxylic acid corresponding to tetracarboxylic dianhydride represented by formula (a1) (ie, 4,4'-oxydiphthalic acid), and alkyl esters of tetracarboxylic acid. Especially, the tetracarboxylic dianhydride represented by Formula (a1) is preferable.

Similarly, as a compound which gives a structural unit (A2), although the compound represented by Formula (a2) is mentioned, It is not limited to it, It may be a derivative|guide_body within the range which gives the same structural unit. As the derivative, tetracarboxylic acid corresponding to tetracarboxylic dianhydride represented by the formula (a2) (ie, 1,2,4,5-cyclohexanetetracarboxylic acid), and an alkyl ester of tetracarboxylic acid can be heard Especially, the tetracarboxylic dianhydride represented by Formula (a2) is preferable.

The tetracarboxylic acid component contains preferably 30 to 90 mol% of the compound providing the structural unit (A1), more preferably 35 to 70 mol%, further preferably 40 to 60 mol%. do.

The tetracarboxylic acid component contains preferably 10 to 70 mol%, more preferably 30 to 65 mol%, and still more preferably 40 to 60 mol% of the compound providing the structural unit (A2). do.

The tetracarboxylic acid component contains the compound providing the structural unit (A1) and the compound providing the structural unit (A2) in total, preferably 50 mol% or more, more preferably 70 mol% or more, More preferably, it contains 90 mol% or more. An upper limit is not specifically limited, A tetracarboxylic-acid component is 100 mol% or less in total of the compound which provides a structural unit (A1), and the compound which provides a structural unit (A2). The tetracarboxylic acid component may consist only of a compound providing a structural unit (A1) and a compound providing a structural unit (A2).

The molar ratio [(A1)/(A2)] of the compound providing the structural unit (A1) to the compound providing the structural unit (A2) in the tetracarboxylic acid component is preferably 30/70 to 90/10. , More preferably, it is 35/65 - 70/30, More preferably, it is 40/60 - 60/40.

The tetracarboxylic acid component may contain arbitrary compounds other than the compound which provides a structural unit (A1), and the compound which provides a structural unit (A2).

As such optional compounds, the above-mentioned aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aliphatic tetracarboxylic dianhydride, and derivatives thereof (tetracarboxylic acid, alkyl esters of tetracarboxylic acid, etc.) can be heard

One type may be sufficient as the compound arbitrarily contained in a tetracarboxylic-acid component, and 2 or more types may be sufficient as it.

Although the compound represented by Formula (b1) is mentioned as a compound which provides a structural unit (B1), It is not limited to it, It may be a derivative|guide_body within the range which gives the same structural unit. As this derivative, the diisocyanate corresponding to the compound represented by Formula (b1) is mentioned. As the compound giving the structural unit (B1), a compound represented by the formula (b1) (ie, diamine) is preferable.

Similarly, examples of the compound to which the structural unit (B2) is given include the compound represented by the formula (b21) and the compound represented by the formula (b22), but it is not limited thereto, and the range in which the same structural unit is given may be a derivative thereof. Examples of the derivative include diisocyanate corresponding to the compound represented by the formula (b21) and the diisocyanate corresponding to the compound represented by the formula (b22). As the compound giving the structural unit (B2), the compound represented by the formula (b21) and the compound represented by the formula (b22) (ie, diamine) are preferable.

The diamine component preferably contains 5-80 mol% of the compound which provides a structural unit (B1), More preferably, it contains 10-70 mol%, More preferably, it contains 30-60 mol%.

The diamine component contains preferably 20 to 95 mol% of the compound providing the structural unit (B2), more preferably 30 to 90 mol%, further preferably 40 to 70 mol%.

The diamine component contains, in total, preferably 50 mol% or more, more preferably 70 mol% or more, more preferably the total of the compound providing the structural unit (B1) and the compound giving the structural unit (B2). Preferably, it contains 90 mol% or more. An upper limit is not specifically limited, A tetracarboxylic-acid component is 100 mol% or less in total of the compound which provides a structural unit (B1), and a compound which provides a structural unit (B2). The tetracarboxylic acid component may consist only of a compound providing the structural unit (B1) and a compound providing the structural unit (B2).

The molar ratio [(B1)/(B2)] of the compound providing the structural unit (B1) and the compound providing the structural unit (B2) in the diamine component is preferably from the viewpoint of improving optical isotropy and chemical resistance is 5/95 to 80/20, more preferably 10/90 to 70/30, still more preferably 30/70 to 60/40. Moreover, from a viewpoint of heat resistance and extending|stretching, Preferably it is 25/75-80/20, More preferably, it is 35/65-65/35, More preferably, it is 35/65-55/45, More preferably is 35/65 to 45/55.

The diamine component may contain arbitrary compounds other than the compound which provides a structural unit (B1), and the compound which provides a structural unit (B2).

As such arbitrary compounds, the aromatic diamines, alicyclic diamines, and aliphatic diamines mentioned above, and those derivatives (diisocyanate etc.) are mentioned.

The number of compounds arbitrarily contained in the diamine component may be one, and 2 or more types may be sufficient as them.

Production of the polyimide resin of the present invention WHEREIN: It is preferable that the diamine component is 0.9-1.1 mol with respect to 1 mol of tetracarboxylic-acid components as for the input ratio of the tetracarboxylic-acid component and diamine component used for manufacture of a polyimide resin.

In addition, manufacture of the polyimide resin of this invention WHEREIN: For manufacture of polyimide resin, other than the tetracarboxylic-acid component and diamine component mentioned above, you can also use an end-blocking agent. As the terminal blocker, monoamines or dicarboxylic acids are preferable. The amount of the terminal capping agent introduced is preferably 0.0001 to 0.1 mol, more preferably 0.001 to 0.06 mol, based on 1 mol of the tetracarboxylic acid component. Monoamine end caps include, for example, methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine , 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. are mentioned, and benzylamine and aniline are preferable. As the dicarboxylic acid end capping agent, dicarboxylic acids are preferable, and a part thereof may be ring-closed. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenonedicarboxylic acid, 3,4-benzophenonedicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, Cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. are mentioned, Phthalic acid and phthalic anhydride are preferable.

There is no restriction|limiting in particular in the method of making the above-mentioned tetracarboxylic-acid component and diamine component react, A well-known method can be used.

As a specific reaction method, (1) a method in which a tetracarboxylic acid component, a diamine component, and a reaction solvent are put into a reactor, stirred at 10 to 110° C. for 0.5 to 30 hours, and then the temperature is raised to perform imidization reaction, ( 2) After dissolving the diamine component and the reaction solvent in the reactor, adding the tetracarboxylic acid component, stirring at 10 to 110 ° C. for 0.5 to 30 hours if necessary, and then raising the temperature to perform imidization reaction; (3) The method of putting a tetracarboxylic-acid component, a diamine component, and a reaction solvent into a reactor, heating up immediately, and performing imidation reaction, etc. are mentioned.

The reaction solvent used for manufacture of polyimide resin should just be what can melt|dissolve the polyimide produced|generated, without inhibiting imidation reaction. For example, an aprotic solvent, a phenol type solvent, an ether type solvent, a carbonate type solvent, etc. are mentioned.

Specific examples of the aprotic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP), N-methylcaprolactam, 1,3-dimethyl Amide solvents such as imidazolidinone and tetramethylurea, Lactone solvents such as γ-butyrolactone (GBL) and γ-valerolactone, Phosphorus-containing solvents such as hexamethylphosphoricamide and hexamethylphosphine triamide Amide solvents, sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane, ketone solvents such as acetone, cyclohexanone, and methylcyclohexanone, amine solvents such as picoline and pyridine, acetic acid (2-methyl Ester solvents, such as oxy-1-methylethyl), etc. are mentioned.

Specific examples of the phenolic solvent include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6 -xylenol, 3,4-xylenol, 3,5-xylenol, etc. are mentioned.

Specific examples of the ether-based solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methyl) ethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, and the like.

Further, specific examples of the carbonate-based solvent include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, and propylene carbonate.

Among the reaction solvents, aprotic solvents are preferable, amide solvents and lactone solvents are more preferable, and lactone solvents are still more preferable. In addition, the reaction solvent may be used alone or in mixture of two or more.

In the imidation reaction, it is preferable to use a Dean-Stark apparatus or the like to perform the reaction while removing water generated during production. By performing such operation, polymerization degree and imidation rate can be raised more.

In the said imidation reaction, a well-known imidation catalyst can be used. Examples of the imidization catalyst include a base catalyst or an acid catalyst.

Examples of the base catalyst include pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine (TEA), tripropylamine, Organic base catalysts such as tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, etc. of inorganic base catalysts.

Examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxybenzoic acid, terephthalic acid, benzenesulfonic acid, paratoluenesulfonic acid, and naphthalenesulfonic acid. The said imidation catalyst may be used individually or in combination of 2 or more types.

Among the above, from the viewpoint of handling properties, it is preferable to use a base catalyst, it is more preferable to use an organic base catalyst, and it is still more preferable to use triethylamine.

The temperature of the imidation reaction is preferably 120 to 250°C, more preferably 160 to 200°C from the viewpoint of suppression of the reaction rate and gelation. Further, the reaction time is preferably 0.5 to 10 hours after the start of outflow of the product water.

[Polyimide Varnish]

The polyimide varnish of the present invention is obtained by dissolving the polyimide resin of the present invention in an organic solvent. That is, the polyimide varnish of the present invention contains the polyimide resin of the present invention and an organic solvent, and the polyimide resin is dissolved in the organic solvent.

The organic solvent is not particularly limited as long as it dissolves the polyimide resin, and it is preferable to use the above-mentioned compounds alone or in mixture of two or more as the reaction solvent used for the production of the polyimide resin.

The polyimide varnish of the present invention may be a polyimide solution in which the polyimide resin obtained by the polymerization method is dissolved in a reaction solvent itself, or may be diluted by further adding a solvent to the polyimide solution.

Since the polyimide resin of this invention has solvent solubility, it can be set as the high-concentration varnish which is stable at room temperature. It is preferable that 5-40 mass % of polyimide resins of this invention are included, and, as for the polyimide varnish of this invention, it is more preferable that 5-20 mass % is included. 1-200 Pa.s is preferable and, as for the viscosity of a polyimide varnish, 1-100 Pa.s is more preferable. The viscosity of a polyimide varnish is the value measured at 25 degreeC using the E-type viscometer.

In addition, the polyimide varnish of the present invention contains inorganic fillers, adhesion promoters, release agents, flame retardants, UV stabilizers, surfactants, leveling agents, defoamers, optical brighteners, crosslinking agents, You may also contain various additives, such as a polymerization initiator and a photosensitizer.

The manufacturing method of the polyimide varnish of this invention is not specifically limited, A well-known method is applicable.

[Polyimide Film]

The polyimide film of this invention contains the polyimide resin of this invention. Therefore, the polyimide film of this invention is excellent in optical isotropy, peelability, and chemical-resistance. The suitable physical-property value which the polyimide film of this invention has is as above-mentioned as <characteristics of polyimide resin>.

There is no restriction|limiting in particular in the manufacturing method of the polyimide film of this invention, A well-known method can be used. For example, after the polyimide varnish of the present invention is coated on a smooth support such as a glass plate, a metal plate, or a plastic, or molded into a film, an organic solvent such as a reaction solvent or a diluent solvent contained in the varnish is heated. and a method of removing it by

As a coating method, well-known coating methods, such as spin coating, slit coating, and blade coating, are mentioned, Spin coating and slit coating are preferable. Especially, a slit coat is more preferable from a viewpoint of workability|operativity that chemical-resistance improves by controlling an intermolecular orientation.

As a method of removing the organic solvent contained in the varnish by heating, after evaporating the organic solvent at a temperature of 150° C. or less to make it tack-free, the temperature above the boiling point of the used organic solvent (not particularly limited, but preferably 200 It is preferable to dry at ~500°C). In addition, it is preferable to dry under an air atmosphere or a nitrogen atmosphere. The pressure of the dry atmosphere may be any of reduced pressure, normal pressure, and pressurization.

Although the method of peeling the polyimide film formed into a film on a support body from a support body is not specifically limited, A mechanical peel-off method, a laser lift-off method, etc. can be used.

Moreover, the polyimide film of this invention can also be manufactured using the polyamic-acid varnish in which polyamic acid is melt|dissolved in the organic solvent.

The polyamic acid contained in the polyamic acid varnish contains, as a precursor of the polyimide resin of the present invention, a compound providing the above-mentioned structural unit (A1) and a compound providing the above-mentioned structural unit (A2) It is a product of the polyaddition reaction of a tetracarboxylic-acid component and the diamine component containing the compound which provides the structural unit (B1) mentioned above, and the compound which provides a structural unit (B2). By imidating this polyamic acid (ring closure by dehydration), the polyimide resin of the present invention as a final product is obtained.

As the organic solvent contained in the polyamic acid varnish, the organic solvent contained in the polyimide varnish of the present invention may be used.

In the production of the polyimide film of the present invention, the polyamic acid varnish may be a polyamic acid solution itself obtained by polyaddition reaction of a tetracarboxylic acid component and a diamine component in a reaction solvent, or may be added to the polyamic acid solution. It may be diluted by further adding a solvent.

There is no restriction|limiting in particular in the method of manufacturing a polyimide film using a polyamic-acid varnish, A well-known method can be used. For example, a polyamic acid varnish is applied on a smooth support such as a glass plate, a metal plate, or a plastic, or is molded into a film, and an organic solvent such as a reaction solvent or a diluent solvent contained in the varnish is removed by heating. to obtain a polyamic acid film, and imidizing the polyamic acid in the polyamic acid film by heating, whereby a polyimide film can be produced.

As a heating temperature at the time of drying a polyamic-acid varnish and obtaining a polyamic-acid film, Preferably it is 50-120 degreeC. As a heating temperature at the time of imidating polyamic acid by heating, Preferably it is 200-400 degreeC.

On the other hand, the method of imidization is not limited to thermal imidization, and chemical imidation can also be applied.

The thickness of the polyimide film of the present invention can be appropriately selected depending on the use, etc., but is preferably in the range of 1 to 250 μm, more preferably 5 to 100 μm, still more preferably 8 to 80 μm, and even more preferably 10 to 80 μm. to be. Practical use as a self-supporting film becomes possible because thickness is 1-250 micrometers.

The thickness of the polyimide film can be easily controlled by adjusting the solid content concentration and viscosity of the polyimide varnish.

The polyimide film of this invention is used suitably as a film for various members, such as a color filter, a flexible display, a semiconductor component, and an optical member. The polyimide film of this invention is used especially suitably as a board|substrate of image display apparatuses, such as a liquid crystal display and an OLED display.

Example

Hereinafter, the present invention will be specifically described by way of Examples. However, the present invention is not limited by these Examples at all.

<Film properties and evaluation>

Each physical property of the film obtained by the Example and the comparative example was measured by the method shown below.

(1) Film thickness

The film thickness was measured using a micrometer manufactured by Mitsutoyo Co., Ltd.

(2) Tensile strength, tensile modulus, and tensile elongation at break (evaluation of elongation)

Tensile strength, tensile modulus of elasticity, and tensile elongation at break were measured using a tensile tester "Strograph VG-1E" manufactured by Toyo Seiki Co., Ltd. in accordance with JIS K7127:1999. The distance between chucks was 50 mm, the specimen size was 10 mm × 70 mm, and the test speed was 20 mm/min.

(3) Glass transition temperature (Tg)

Using a thermomechanical analysis device "TMA/SS6100" manufactured by Hitachi High-Tech Sciences, Inc., the temperature sufficient to remove the residual stress under the conditions of a sample size of 2 mm × 20 mm, a load of 0.1 N, and a temperature increase rate of 10° C./min in tension mode. The temperature was raised to , to remove the residual stress, and then cooled to room temperature. Thereafter, the test piece elongation was measured under the same conditions as the treatment for removing the residual stress, and the point where the inflection point of elongation was observed was determined as the glass transition temperature.

(4) total light transmittance, and yellow index (YI)

The total light transmittance and YI were measured using the color and turbidity simultaneous measuring instrument "COH7700" manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS K7136.

(5) Haze

The measurement was performed using the color and turbidity simultaneous measuring instrument "COH7700" manufactured by Nippon Densoku Industries Co., Ltd. in conformity with JIS K7361-1.

(6) Thickness phase difference (Rth) (evaluation of optical isotropy)

The thickness retardation (Rth) was measured using an ellipsometer "M-220" manufactured by Nippon Spectroscopy Corporation. The value of the thickness retardation in the measurement wavelength 590nm was measured. On the other hand, Rth is expressed by the following formula when the maximum in-plane refractive index of the polyimide film is nx, the minimum is ny, the refractive index in the thickness direction is nz, and the thickness of the film is d.

Rth=[{(nx+ny)/2}-nz]×d

On the other hand, Rth in terms of 10 µm is Rth when the value of d is 10 µm.

(7) Solvent resistance (PGMEA resistance) (Evaluation of chemical resistance)

The polyimide film formed into a film on the glass plate was immersed in the solvent at room temperature, and it was confirmed whether there was no change in the film surface. In addition, as a solvent, propylene glycol monomethyl ether acetate (PGMEA) was used.

The evaluation criteria of solvent resistance were as follows.

A: There was no change in the film surface.

B: A crack entered the film surface, or the film surface was dissolved.

<Abbreviation of ingredients, etc.>

The tetracarboxylic acid component and the diamine component used in the Example and the comparative example, and its abbreviation are as follows.

(Tetracarboxylic acid component)

ODPA: 4,4'-oxydiphthalic anhydride (manufactured by Manak Corporation; compound represented by formula (a1))

HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (a2))

(diamine component)

BAPS: bis[4-(4-aminophenoxy)phenyl]sulfone (manufactured by Seika Corporation; compound represented by formula (b1a))

M-BAPS: bis[4-(3-aminophenoxy)phenyl]sulfone (manufactured by Seika Corporation; compound represented by formula (b1b))

1,3-BAC: 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (b21a))

1,4-BAC: 1,4-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (b21b); trans ratio 40%)

1,4-BACT: 1,4-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (b21b); trans ratio 85%)

3,3'-DDS: 3,3'-diaminodiphenylsulfone (manufactured by Seika Co., Ltd.)

<Production of polyimide resin, varnish and polyimide film>

Example 1

In a 500mL 5-neck round-bottom flask equipped with stainless steel half-moon stirring blade, nitrogen inlet tube, cooling tube, Dean-Stark, thermometer, and glass end cap, 8.650g (0.020mol) of BAPS, 11.380g of 1,4-BACT (0.080 mol) and 45.710 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) were added, and stirred at a system internal temperature of 70° C., a nitrogen atmosphere, and a rotation speed of 150 rpm to obtain a solution.

To this solution, 15.511 g (0.050 mol) of ODPA, 11.209 g (0.050 mol) of HPMDA, and 11.427 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) were added at once, and then triethylamine ( 0.506 g (manufactured by Kanto Chemical Co., Ltd.) was added, heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The components to be distilled were collected, and while the number of rotations was adjusted according to the increase in viscosity, the temperature in the reaction system was maintained at 190° C. and refluxed for 2 hours.

Then, 187.350 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) is added so that the solid content concentration is 15% by mass, the temperature inside the reaction system is cooled to 100° C. got varnish.

Then, on a glass plate, the obtained polyimide varnish is applied by spin coating, held on a hot plate at 80° C. for 20 minutes, and then heated in an air atmosphere at 260° C. in a hot air dryer for 30 minutes, and the solvent is evaporated. and a film was obtained.

Example 2

Implemented except that the amount of 1,4-BACT was changed from 11.380 g (0.080 mol) to 9.958 g (0.070 mol) and the amount of BAPS was changed from 8.650 g (0.020 mol) to 12.975 g (0.030 mol) By the method similar to Example 1, the polyimide varnish with a solid content concentration of 15 mass % was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 3

Implemented except that the amount of 1,4-BACT was changed from 11.380 g (0.080 mol) to 8.535 g (0.060 mol) and the amount of BAPS was changed from 8.650 g (0.020 mol) to 17.300 g (0.040 mol) By the method similar to Example 1, the polyimide varnish with a solid content concentration of 15 mass % was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 4

Implemented except that the amount of 1,4-BACT was changed from 11.380 g (0.080 mol) to 7.113 g (0.050 mol) and the amount of BAPS was changed from 8.650 g (0.020 mol) to 21.625 g (0.050 mol) By the method similar to Example 1, the polyimide varnish with a solid content concentration of 15 mass % was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 5

A polyimide varnish having a solid content concentration of 15% by mass was obtained in the same manner as in Example 4 except that 7.113 g (0.050 mol) of 1,4-BACT was changed to 7.113 g (0.050 mol) of 1,4-BAC. .

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 6

A polyimide varnish having a solid content concentration of 15% by mass was obtained in the same manner as in Example 4 except that 7.113 g (0.050 mol) of 1,4-BACT was changed to 7.113 g (0.050 mol) of 1,3-BAC. .

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 7

Except for changing 7.113 g (0.050 mol) of 1,4-BACT to 7.713 g (0.050 mol) of bis(aminomethyl)novonane (isomer mixture: manufactured by Tokyo Chemical Industry Co., Ltd.; compound represented by formula (b22)) , A polyimide varnish having a solid content concentration of 15% by mass was obtained by the same method as in Example 4.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 8

A polyimide varnish having a solid content concentration of 15% by mass was obtained in the same manner as in Example 4 except that 21.625 g (0.050 mol) of BAPS was changed to 21.625 g (0.050 mol) of M-BAPS.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 1

A polyimide varnish having a solid content concentration of 20% by mass was obtained in the same manner as in Example 4 except that 21.625 g (0.050 mol) of BAPS was changed to 12.415 g (0.050 mol) of 3,3'-DDS.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 2

The amount of BAPS was changed from 8.650 g (0.020 mol) to 43.249 g (0.100 mol), the amount of HPMDA was changed from 11.209 g (0.050 mol) to 22.417 g (0.100 mol), and ODPA, 1,4-BACT was A polyimide varnish having a solid content concentration of 20% by mass was obtained in the same manner as in Example 1 except that it was not used.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 3

The amount of M-BAPS was changed from 21.625 g (0.050 mol) to 43.249 g (0.100 mol), the amount of HPMDA was changed from 11.209 g (0.050 mol) to 22.417 g (0.100 mol), ODPA, 1,4- A polyimide varnish having a solid content concentration of 20% by mass was obtained in the same manner as in Example 8 except that BACT was not used.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

The above physical properties were measured and evaluated for the polyimide films obtained in Examples and Comparative Examples. A result is shown in Table 1.

[Table 1]

As shown in Table 1, it turns out that the polyimide film of an Example has favorable optical isotropy, and also excellent also toughness and chemical-resistance. Comparative Example 1 was excellent in optical isotropy and chemical resistance, but was inferior in elongation. Comparative Example 2 was inferior in optical isotropy, chemical resistance, and elongation. Comparative Example 3 had good optical isotropy, but poor stretching and chemical resistance.

Therefore, using ODPA and HPMDA as a tetracarboxylic acid component, and using BAPS or M-BAPS as a diamine component, and an alicyclic diamine such as 1,3-BAC, 1,4-BAC, 1,4-BACT, A polyimide film can be used suitably as a plastic substrate, such as a liquid crystal display, an OLED display, and a touch panel, as a film excellent in optical isotropy, chemical-resistance, and elongation.

Claims (5)

A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine,
The structural unit A includes a structural unit (A1) derived from a compound represented by the following formula (a1) and a structural unit (A2) derived from a compound represented by the following formula (a2),
The structural unit B is a structural unit (B1) derived from a compound represented by the following formula (b1), a structural unit (B21) derived from a compound represented by the following formula (b21), and a compound represented by the following formula (b22) A polyimide resin comprising at least one structural unit (B2) selected from the group consisting of a structural unit (B22) derived from
[Formula 1]

The method of claim 1,
The polyimide resin whose ratio of the structural unit (A1) in the structural unit A is 30-90 mol%, and the ratio of the structural unit (A2) in the structural unit A is 10-70 mol%. 3. The method of claim 1 or 2,
The polyimide resin wherein the proportion of the structural unit (B1) in the structural unit B is 5-80 mol%, and the proportion of the structural unit (B2) in the structural unit B is 20-95 mol%. A polyimide varnish in which the polyimide resin according to any one of claims 1 to 3 is dissolved in an organic solvent. The polyimide film containing the polyimide resin in any one of Claims 1-3.